package LuoGu.入门.NAndK;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int k = s.nextInt();
        double n = 1;
        double all = 1.0;
        while(all<=k){
            n++;
            all+=(1/n);
        }System.out.printf("%.0f",n);
    }
}
